Notes: Measuring the Position Angle of a Flat Galaxy: it is the angle subtended by the major axis of the galaxy referenced to the North, moving counter- clockwise towards East, and then South. The maximum PA can be not larger than 180 degrees. Example: a galaxy whose major axis is East-West has a PA of 90 degrees. A galaxy whose major axis points halfway between North and East has a PA of 45 degrees. If a galaxy's major axis points halfway between East and South, then it has a PA of 135 degrees. (Bob Erdman)